This is a very popular question that many couples have to decide when they are planning their wedding. Some couples don't want to go through the hassle and the time to organize all of their guests, while others feel like it is very important to keep everyone organized.
When I have this discussion with couples, I like to take into consideration what type of feel and the type of food service they would like for their wedding; is it more of a cocktail party, buffet style, family style, or plated. Each situation would render a different option.
Usually when your reception is more like a Cocktail Party, there is very limited seating anyways; you want people to move around and talk. Normally you would offer a few rounds with chairs, especially if you have guests that are not able to stand for long periods of time. Depending on size of your space will really determine how many seated tables you should offer but in general, if most guests can stand, I would say about 33% of your guest count. Along with the seated tables, have lot of high top cocktail tables. This offers a place for your guests to place their drinks and plates down so they don't have to try and juggle both.
Another option instead of offering tables and chairs is to have intimate seating areas. There are many vendors that you can rent couches and comfy chairs to make your rental space feel more cozy. This is a more modern look but can help soften any venue and make it feel more homey and warm.
Cocktail style receptions can be decieving if you are thinking this will be the way that you will cut costs. Although you are serving less food, you will most likely be passing hor d'euves and possibly specialty drinks. This will require more staff. Also, those single bites can be pricey!! It is very important to meet with your caterer and discuss your options - possibly offering an appitizer table and only passing 2 or 3 options.
Have you attended a Reception that was more like a Cocktail Party? What did you think?